Ring Syntheses Involving Formation of Two Bonds Fragments

Ring Syntheses Involving Formation of Two Bonds [3 + 2] Fragments 

Only approaches to the uncondensed imidazole ring are available using this strategy. 

The most convenient method of making a-aminoaldehydes is by reduction of a-amino acid esters using sodium amalgam [5, 6] by what has come to be known as the Akabori method. Alternatively, an a-halogenocarbonyl compound can be converted via the Gabriel synthesis into the aminocarbonyl 

Direct aminolysis of an a-bromoketone also gives the a-aminoketone provided that conditions are carefully controlled [12]. 

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